1. Field of the Invention
This invention is directed to an auxiliary power take-off assembly and method for a truck, and, more particularly, to such an assembly which mounts and drives a hydraulic pump or the like via an auxiliary drive belt. The auxiliary drive belt is driven via an auxiliary drive pulley attached immediately behind a fan pulley provided by the original engine manufacturer.
2. Description of the Related Art
Power take-off (PTO) assemblies for adapting an original equipment manufacturer's (OEM) engine on a tractor or truck to drive an auxiliary device, such as a front mounted hydraulic pump or the like, are well known.
In known PTO assemblies, the auxiliary hydraulic pump is typically located within the engine compartment intermediate the engine and the coolant radiator. In such assemblies, an auxiliary belt drive pulley is typically attached to the engine crankshaft between an OEM drive pulley and the cooling radiator. The attachment of such an auxiliary drive pulley in front of the OEM pulley necessitates attaching an extension on the crankshaft to accommodate the auxiliary pulley. Also, an extension is required on the water pump shaft to thereby move the cooling fan forward toward the radiator to accommodate the auxiliary drive belt. This known arrangement presents a number of problems.
The attachment of an auxiliary drive pulley in front of the OEM pulley on the crankshaft increases the bending load on the crankshaft. In addition, the attachment of an extension to the water pump shaft substantially increases the load on the water pump shaft due to the increased torque from the fan extension. Furthermore, the movement of the fan forward toward the radiator tends to decrease the effectiveness of air flow from the fan, thus increasing the heat load on the radiator, and the reduced spacing between the fan and the radiator increases the chances of the fan hitting the radiator.
It is clear hen, that a need exists for a PTO assembly and method for allowing an auxiliary rotary drive implement, such as a hydraulic pump, to be added to an OEM engine. Such an assembly and method should preferably be capable of installation without the need to move the OEM cooling fan forward toward the radiator. Furthermore, such an assembly and method should be relatively simple to install and should minimize alterations to OEM equipment.